I think this is insect swarm, but I'm not sure. Whenever it's cast on my party by high-level druids, it doesn't disappear from the character until the character dies. It persists after combat, through rests, and through area transitions. There are no druid or cleric spells to heal it.

Same problem here. Happened with the Ogres in front of the Cave in Elmshore. Got rid of the Insect Swarm like Logos said, only Itumaak the Fox heals to fast, to die of the condition.

Hello, 

 

Thank you for reporting this issue. We've discovered the root cause and this should be fixed in the next patch. Thanks for the support!